Medical images play an important role in quality patient care. Many diagnostic and treatment decisions are heavily dependant on image data (including images and reports). In todays medical environment, most patients have multiple encounters at geographically separate locations, with image data dispersed across a number of sites. The inability to share medical image data across separate organizations results in significant problems: inadequate patient care due to absent data, delayed care due to ineffective image distribution, and significant increases in cost and potential health risk due to duplicate image acquisition. Sharing image data through a network for image exchange will lead to better informed medical decisions, better analysis of medical outcomes, reductions in unnecessary expenses and improvements in the quality and safety of patient care. The value of patient care will be enhanced when systems at different locations are capable of managing, exchanging and displaying medical information in its many forms, including images. In addition, an optimal solution could dramatically reduce overhead on the health care infrastructure. National Institute of Biomedical Imaging and Bioengineering (NIBIB) NIBIB has funded several projects over the last few years to establish basic infrastructures to promote the exchange of medical images across broad geographic areas within the United States. Several critical factors have been identified in those efforts in order to develop a successful image sharing system, e.g. security, identity, privacy and confidentiality, consent and permissions, bandwidth, ease of use, etc.